It’s nature herself! It’s invincible! This effect is called Laminar flow. It happen when water flows so smoothly it looks solid.
Laminar flow in fluid dynamics is characterized by fluid particles travelling in parallel layers passing each other without much or any mixing, at low velocities neighboring layers slide past one another like playing cards, on camera it appears frozen.
The flow of blood inside the blood vessels is generally laminar, meaning that it flows smoothly in parallel layers with little mixing between layers. However, the flow can become turbulent in certain conditions, such as when there is a narrowed or blocked area in the vessel, or when the blood flow is increased. This can lead to increased resistance to blood flow and increased risk of clot formation. So, keep it laminar, keep it healthy!